Method of producing flexible metal hose



Mar h K. H. EVERT 2,313,329

METHOD OF PRODUCING FLEXIBLE METAL HOSE Fi l ed June 16, 1941 3 sheets-She t 1 March 9, 1943. H. EVERT METHOD OF PRODUCING FLEXIBLE METAL HOSE Filed June 16, 1941 3 3 SheetsvSheet' 2 I March 9, 1943.

METHOD OF PRODUCING FLEXIBLE METAL HOSE Filed June 16, 1941 I L '3 Sheets-Sheet 3 L 6%20/227 uuunun ffaf/ 7271/6 K. H. EVERTL 1,313,329

Patented Mar. 9 1943 METHOD OF PRODUCING FLEXIBLE METAL HOSE Karl n. am Elmhurst, m.

Application June s, 1941, Serial No. 398,272 3 Claims. (01. 219-10) The present invention relates to metallic fiexible conduits, and more particularly to the Y method of producing the same.

Metal conduits or hose of this type are formed from preformed metallic strips helically wound in a suitable rotating device whereby the adjacent edge portions of the convolutions of the strip are joined, as by brazing or otherwise, to. efi'ect a seam. The finishedconduit is longitudinally corrugated in shape. I

The present invention comprehends a novel method of producing a novel metal hose or conduit, using also novel mean to effect the same.

I run the strip of metal through a suitable or ribs or the like, alongv which smooth surface the coilsor convolutions of the conduit will slide. 1

The roller or rollers are so located as to position. the adjacent convolutions in given spaced relation whereby the adjacent fianges will overlap for joining. These flanges are at the base of the helical trough formed between the convolutions, and located against or adjacent the smooth cylindrical surface of the mandrel, preferably at the locus of. first contact of the profiled strip with the mandrel as the strip initially becomes associated with the mandrel.

Other rollers may be used and located at different-points around the mandrel so as to guide the movement of the convolutions around the mandrel. These rollers may be spaced from the mandrel so that the convolutions will not touch the mandrel but will spacedly encircle it. In such case the axial movement or feed of the convoluv g tions relative to the mandrel will be greatly facilitated, withipractically no friction nor resistance.

Preferably,'one' of the discs, such as the lead disc, is designed to weld the overlapping adjacent flanges.- By welding at a point where the profiled strip initially contacts the mandrel then the convolutions are fixed inrelation and will turn about and slide along the; mandrel as a-"single welding a unitary corrugated tube;

An important novel feature is the the base of the trough between the adjacent convolutions, that is, adjacent to the surface of the mandrel. This welding forms a continuous seam between the overlapping flanges and for the full width of the overlapping portions of such flanges.

The invention also comprehends a a part thereof the provision of novel means for gathering the convolutions, that is, spacing the coils or convolutions closer together forthe finished profile of the coil or conduit fed from the mandrel. This novel means comprises a roller or rollers which stress the coils or convolutions to make them gather closer together. In doing so the outer diameter is increased, the inner diameter remaining the same, that is, approximately that of the outside diameter of the mandrel.

Otherobjects, advantages, capabilities, features, process steps,'and the like are comprehended by the invention as will later appear and as are inherently possessed b y the invention.

Referring to the drawings:

Fig. 1 is a conventional side view of a chine embodying the invention;

Fig. 2 is a transverse view, on an enlarged scale, with parts in section, of the invention;

Flg. 3 is a fragmentary side view, on a further tional view of diiferent types of rollers used in.

the invention;

Figs. 14. and 15 are part transverse views and part end views of the invention showing the novel meansfor driving the rollers about the tube; and

Fig. 16 is a fragmentary view for illustration of the drive means for a roller.

Referring more in'detall to the drawings, for illustrating the invention, the/preformed or profiled strip l is helically wound upon a mandrel 2 having a smooth cylindrical outer surface upon which the strip is wound. and along which the .tube slides axially to be fed oil to a take-up means. The mandrel is axially stationary but preferably rotates at the sameor faster angular speed as or than the tube, yet the invention comprehends the use of a mandrel whichmay not rotate. In the latter case as the tube turns over the mandrel there would be a little more friction between the tube and the mandrel but that would not be sufi'lcient to affect the eiilcient production of the tube in accordance with my invention. Suitable lubrication can be used between the mandrel and the tubeif desired or found necessary. 7

The tube is made from metal strips, such as stainless steel, or the like. The strip is forced through any suitable preforming or profiling device (not shown) to give the strip the desired cross-sectional form or profile, and longitudinal curve to wind around the mandrel.

In the present invention it is preferable to profile the strip in U-shape with the bend of the U forming the outer crest 3 of the strip, and with the legs of the U formed with lateral flanges 4 and 5 which when united constitute a part of the inner trough 6 between adjacent convolutions of the profiled strip when helically wound on the mandrel 2. As the strip is hellcally wound on the mandrel one of the flanges, such as flange 4, will lie in contact with the stir-- face of the mandrel, as. at the top, as shown, and the other flange, such as'flange 5 of the succeeding convolution of the strip, will lie upon and in contact with the adjacent flange 4 of the preceding convolution of the strip. These overlapping fianges are later welded together as hereinafter described. 1

It is preferable to have these flanges overlap along a narrow width where the welded seam is produced so that there will be no fissure between the overlapping portions of the flanges on either or both sides of thewelding trace, and also for economy wherein strips of less width may be used than was heretofore required, when bonding by solder or by brazing.

The strip is helically wound upon or about the outer cylindrical surface of the mandrel as the strip is fed out of the preforming or profiling device and moved in betweenthe mandrel and a series of rollers I, la, 8 and 9 (conventionally shown in Fig. 2) having suitable profiled peripheries conforming to the inter-profiles of the convolutions of the strip. These rollers are rotatable about respective axes generally parallel with the axis of the mandrel and the tube but normal to the circumferential portions of the convolutions contacted thereby, and are distributed around the mandrel, besides being progressively axially spaced in accordance with the pitch of the helically wound strip. These rollers are principally for holding the convolutions of the strip properly spaced, and for pressing against the overlapping flanges 4 and 5 to effect a correct welding of such flanges, as later explained.

These rollers may be of simple form as shown in Figs. 2, 3 and 5, preferably composed of insulating material (although that is not wholly necessary) more or less in disc form and with a tapered periphery iii, to easily enter between convolutions of the strip, and the pressing periphery I l. The thickness of these rollers gauges the spreadror spacing of such convolutions. The

periphery ll of the roller 1 presses against the flange 4 to hold it in contact with the mandrel, and the periphery ll of the roller 1a presses against the overlapping flange 5 to hold it in good contact with the underlapping flange 4 and the surface of the mandrel I.

The axial spacing of these rollers is such that as the entering convolution from the preforming device passes to the mandrel the first roller or rollers will correctly position or direct such convolution axially relative to the previously formed convolution; the second and third rollers, as rollers Ia and 8, will hold such adjacent convolutions properly spaced, and the fourth roller, as roller 9, will guide the convolutions into their helical paths for axial feed of the tube along the mandrel in the direction of the arrow shown in Fig. 3.

One of these rollers may be a welding roller, such as roller Ia. In such casethe body of the roller will be composed of electrically insulating material and will include a central metal or carbon disc I! (see Fig. 6) constituting one of the welding electrodes, for conduction of the electrical energy for welding at the periphery I3 while applying pressure to the flanges 5 and 4, the mandrel l constituting the other of the welding electrodes.

The rollers may be of the form shown in Figs. 10 and 11, which are useful when working with strips having high altitude convolutions. In this case each roller may have a pair of grooves 14 and I5 with an intermediate annular pressing periphery ii for functioning in the trough between adjacent convolutions for maintaining proper spacing or spread and for pressing the flanges thereof, and with lateral rims i1 and i8 so spaced as to span the adjacent convolutions, and to contact the opposite remote sides of the adjacent convolutions, as shown in Fig. 10. By such means the profile of the convolutions is maintained, beside keeping them properly spaced for the welding function to be performed.

Any of these rollers may act as the welding electrode. In such case the body of the roller serving as the welding electrode (see Fig. 11) will be made of electrically non-conducting material l9. and include a central metal or carbon disc 20 to carry the current, the welding being effected at the periphery 2| of such disc.

In the case of using the type of roller shown in Fig. 11, in such a position as shown at la in Fig. 2, the use of other rollers at positions 8 and 9 in Fig. 2 would not be necessary, because the roller at position Ia would perform all the functions of maintaining the relation of the adjacent convolutions, and welding them together by way of their adjacent over-lapping flanges. However, because the tube would be usually larger than the mandrel, the use of rollers 8 and 9 would be useful to hold the tube substantially coaxial or central with the mandrel. After the strips are welded they will wind or turn about the mandrel together as a unit. All that would be necessary when starting the winding of the strip would be to direct, in any suitable manner, the initial end of the profiled strip into a curved path around the mandrel for the first convolution to the point where it becomes welded to the next convolution. After that the strip will wind perfectly about the mandrel as the adjacent convolutions which are welded together proceed in helical path from the point of welding.

The welding is effected electrically between the contacting points of the rotary electrode and the mandrel. The desired number of electrical energy impulses for a given unit. of length of the line of welding or welding trace may be used. This relation may be so chosen that the welding spots will so overlap that there will be a substantially continuous welded seam between the flanges 5 and 4 whereby the tube will be fluid tight, and the width of the welded seam will be suflicient to avoid flanges.

flssures between the flanges at the edges of the It it were assumed that the welding took place along the helical line of the crest 3 of the convo- I the helical trough line instead of along the helical crest line, the work can be speeded up 50%. That is, for obtaining z u spots along the helical trough line per unit of time the tube can be, rotated 50% faster and fed off the mandrel 50% faster. To increase production 50% in this kind of work is immense and not a matter that would be apparent from the methods and means previously used.

As the profiled strip is wound on the mandrel 2 it travels in screw-fashion, that is, the tube rotates about the axis of the mandrel and also progresses axially in proportion to the pitch of the helical form of the convolutions and the speed of rotation. This may be called the feed-oil from the rolls. Y

.The strip may have two or more U-sh'aped' portions between the side flanges. In Fig. 12 the strip is shown with two U-shaped portions 3a and 3b between the side'flanges laand lb, and in Fig. 13 the strip is shown with thre U-shaped portions has compressing and supporting rims 28 and 28 at each side of the convolution to be axially compressed.

It is preferable that the rollers be driven. In Fig. 14 is shown means for driving the rollers as shown in Figs. 2 and 3, and in Fig. 15 is shown means for driving the rollers as shown in Figs. 7

and 8. In both cases the drive means is of generally annular iorm to surround the rollers to be driven and "to be clear of the tube and the mandrel.

In both cases the driving means is shown as having an annular driving ring 21 having inner 3a, 3b and 30 between flanges la and lb. In such cases rollers lb and lc ior guiding and placing the convolutions would be used as shown in Figs. 12 and 13. The disc part of such'roller pressing the adjacent flanges 4b and latogether would act as the welding roller to weld such flanges together.

The disc electrodes shown in Figs. 6 and 11,

, corresponding to the disc electrode'l2a shown in Figs. 12 and 13, may have an enlarged rim l2b, as shown in section in Fig. 12. Any or all oi. the electrodes may use such rim when and where desired. In such case the sides of the peripheral.

portions of the rollers will be more' sharply ta: pered or bevelled so as to leave sufllcient insulating air spaces at both sides of 'the enlarged rim l2b. See Fig. 12. "Alon the feed-oi! path of the tube it is desirable to compress the convolutions. See Figs. 7 and 8. This may be eflected by the use of compressing rollers 22, 23 and 2. These rollers may be of the general form shown in Fig.3, but thinner and more closely axially spaced. They also are preferably rotatable on axes, which are at a normal to the convolutions being compressed, and are suitably arranged angularly'about the tube, whereby two adjacent rollers may have overlapping portions between which a convolution of the tube may be axially squeezed or compressed. As for example, when. convolution 25 passes between rollers 22 and 22 it is given a decreased axial dimension and increased outward radial dimension, .as shown in Fig. 8.- When the convolution 26 passes between rollers 28 and 24} it is 7 outer diameters. The inner diameter oi the convolutions remains the same because of the trough portions bearing onthe surface of the mandrel 2.-

lithe metal used is thin and has a tendency to be weak then the rollers 22, 23 and 24 may be of teeth 28 and rotatably supported between rollers or idlers 29. Meshing with the teeth 28 are spiral gears 30 (see particularly Fig. .16) flxed to shafts 3| leading and secured to rollers I, la, 8 and 9 (see .Fi 14 and Figs. 2 and 3) and to rollers 22, 23 and 24 (see Figs. 7 and 8, and Fig. 13). The annular gear 21 may be rotated by a suitable driving gear 32. The shafts II are at an angle to the axis of the annular gear 21 and at a normal to the convolutions to be acted upon by the rollers I, la, 8 and 9, and 22, 23 and 24 as the case may be.

As the tube now feeds of! it may be taken-up by a suitable take-off device and wound on a suitable wind-up spool or reel.

rected flange extending along each edge of the' profiled strip, comprising the steps of guiding said profiled strip into a helical path around a smooth faced cylindrical mandrel with the flanges or the strip proximately encircling said smooth faced mandrel and with a flange in each convolution of the guided strip in overlapping relation with the other flange in the next preceding convolution whereby a helical trough is provided radially outwardly of said overlapping flanges, said guiding of the strip acting to maintain said convolutions in given spaced relation axially for a given overlap of said flanges, pressins said flanges together and against said smooth faced mandrel at a locus through which said flanges are helically moved by applying a force radially outwardly of the tubing upon aportion further decreased i axial dimension and in of the inner of said overlapping flanges while applying a second force upon the outer side of said outer flange portion contiguous to said inner flange portion, said second force comprising a force component directed oppositely to the' radially outwardly applied force for coacting therewithin pressing said flange portion together and a force component directed tangentially of the tubing for causing the same to rotate and thus advance the overlapping flanges through the locus where said forces are applied,

and welding said flanges at said locus while the flanges are pressed against said mandrel at said locus by passing an electric current through said flan es to said mandrel which acts as an electrode to eirect a resistance weld o! the flanges.

2. The method of making flexible tubing from a strip or bendable weldable material having an the form as roll er 2'| shown in Fig. 9, which roller 7;

undulated transverse profile and a laterally directed flange extending along each edge of the proflled strip, comprising the steps of guiding said profiled strip into a helical path around a smooth faced cylindrical mandrel with the flanges of the strip proximately encircling said smooth faced mandrel and with a flange in each convolution of the guided strip in overlapp g relation with the other flange in the next preceding convolution whereby a helical trough is provided radially outwardly of said overlapping flanges, said guiding of the strip acting to maintain said convolutions in given spaced relation axially for a given overlap of said flanges, pressing said flanges together and against said smooth faced mandrel at a locus through which said flanges are helically moved by applying a force radially outwardly of the tubing upon a portion of the inner of said overlapping flanges while applying a second force upon the outer side of said outer flange portion contiguous to said inner flange portion, said second force comprising a force component directed oppositely to the radially outwardly applied force for coacting therewith in pressing said flange portions together and a force component directed tangentially of the tubing for causing the same to rotate and thus advance the overlapping flanges through the locus where said forces are applied but wherein said tangential force component is also directed diagonally of the tubing for advancing it axially along the mandrel during the rotation of the tubing, and welding said flanges at said locus while the flanges are pressed against said mandrel at said locus. by passing an electric current through said flanges to said mandrel which acts as an electrode to eil'ect a resistance weld of the 3. The method of makingflexible tubing from amassea strip of bendable weldable material having an undulated transverse proflle and a laterally directed flange extending along each edge of the proflled strip, comprising the steps of guiding said proflled strip into a helical path around a smooth faced cylindrical mandrel with the flanges of the strip proximately encircling said smooth faced mandrel and with a flange in each convolution of the guided strip in overlapping relation with the other flange in the next preceding convolution whereby a helical trough is provided radially outwardly of said -overlapping flanges, said guiding of the strip acting to maintain said convolutions in given spaced relation axially for a given overlap of said flanges, applying a plurality of forces radially outwardly of the tubing upon respective circumferentially spaced portions of the inner overlapping flange while applying a second plurality of forces upon circumferentially spaced portions of the outer overlapping flange, said second forces comprising radially inwardly directed force components respectively cooperating with said radially outwardiy directed forces in pressing the aforesaid portions of the inner overlapping flange against contiguous portions of the outer flange, said second forces also including force components directed tangentially oi the tube for causing the same to rotate and thus advance the overlapping flanges through the zones at which the forces are applied, welding said flanges at said locus while the flanges are pressed against said mandrel at said locus by passing an electric current through said flanges to said mandrel which acts as an electrode to effect a resistance weld of the flanges.

KARLEEVERT. 

